Good game!
You've done a great job for your first jam , Its really surprising that you made this all alone , not using assets is pretty rare in game jams so you should be proud of yourself for that.
The idea fits the theme pretty well too and I think it have potential. Also I like the inventory system, and how you need to buy a bag to carry your items around.
Things that will make your game better:
- Fixing the lag problem when particles happen for the first time.
- Make the items (more importantly the tools) fixed when the player holds them since they are kinda hard to use especially the shovel , its hard to dig or fight when the shovel keeps moving around.